The deer mouse (Peromyscus maniculatus) and co-generic species are among the most abundant, species, and widely distributed North American mammals. Ranging from Alaska to Central America and occurring in many natural habitats they are frequently used as models to study the fundamental processes underlying adaptive physiology and behavior and are also used to monitor environmental toxicology. They directly affect many aspects of human health in the United States as reservoirs for infectious disease organisms. Established in 1985, the PGSC provides a reliable source of these animals and related materials to the national scientific and educational communities. The Stock Center proposes to continue providing peromyscines for biomedical and related research, to promote the species and its advantages, and to improve the usefulness of Peromyscus as a laboratory model. One aim is the development of cryopreservation technology for Peromyscus germinal material, thereby enabling economical preservation of mutant stocks. Another aim in the next several years is the development of a Peromyscus genetic map composed of polymerase chain reaction (PCR) based markers. A benefit of the nearly completed human and laboratory mouse genome projects is the ready application of that information to non-traditional species such as Peromyscus. In Peromyscus there are numerous questions of interest to biomedical and basic researchers for which genomic approaches would likely be worthwhile.